The framework

Gaps, not qualities

RUCF measures gaps, not qualities. A gap is the distance between what a user intended, what the product cost them, and what they believe happened. Every gap carries a cost, a confidence and an expiry date.

Layer 1: three measures

Intent. What the user came to do, in their words. A job with a success condition attached, not a persona. “Find out whether this covers my situation before I hand over a card number.”

Friction. What it cost them, in four countable currencies: time to outcome, attempts before success, assistance sought, and abandonment at each decision point.

Perception. What they believe happened. Effort felt, confidence in the result, willingness to repeat.

The discipline that makes this work: friction is measured only from behaviour, perception only from report, and the two are never allowed to inform each other during collection. If they contaminate, everything downstream collapses.

Fig. 01

Layer 1 · three measures, three channels

Layer 2: three gaps

Effectiveness gap. Intent against friction. Did they get what they came for, at what cost. Every existing framework measures this, and it is the least interesting of the three.

Awareness gap. Friction against perception. Does the user know what the product cost them. RUCF exists for this gap.

Expectation gap. Intent against perception. Did they get what they thought they would get. This is the gap that produces churn at products with excellent usability. Nothing is broken. It was not the thing they were told it was.

Fig. 02

Layer 2 · three gaps between three measures

Layer 3: the say-do matrix

The awareness gap resolves into four states with four different correct treatments. Applying the wrong one is worse than doing nothing, because it spends the budget the right one needed.

Fig. 03

Layer 3 · four states, four treatments

Read the full matrix ›

Layer 4: confidence

Two of these are deliberately uncomfortable.

Expert opinion is the weakest evidence in the system. Anything a model classified enters at 0.50 and stays there until a human validates a sample, at which point it is promoted to the class of the validation method. A framework that discounts AI evidence in its own arithmetic is more trustworthy than one that markets AI as a feature.

Confidence then decays on deploy, not on the calendar. confidence × 0.8 per release touching the measured surface, plus a slow time half-life of twelve months for reported evidence and eighteen for observed, because user expectations drift even when your product does not.

Fig. 04

Layer 4 · what evidence is worth, and for how long

Layer 5: priority

priority = recoverable cost × confidence ÷ effort

Recoverable cost is stated in your currency: abandonment times traffic times value per completion, or support contacts times cost per contact, or seconds lost times sessions for an internal tool.

Confidence enters the priority calculation directly, so a large cost you are unsure about ranks below a smaller cost you have observed. Every prioritisation model that omits confidence gets used to justify expensive work on a guess.

Fig. 05

Layer 5 · the cheaper finding outranks the bigger guess

Layer 6: the loop

Measure, diagnose, treat, ship, expire, measure again. Shipping expires the evidence, which raises that surface back up the queue automatically.

Fig. 06

Layer 6 · the loop closes itself

How the loop runs ›

The practice ledger

Added in v2.1 · September 2026

The six layers measure a product. The ledger measures the person running them, using the same evidence rules. It holds three readings, all taken from records and none from memory.

attribution rate = treatments meeting their written criterion ÷ treatments shipped
hour yield       = (signal hours + evidence hours) ÷ logged hours
capture ratio    = fee ÷ (recovered cost × confidence)

Attribution rate says whether the work was good, and it only counts criteria written before the result existed. Hour yield says whether the time was well spent: each logged hour is classed as signal, evidence, receipt or drift when the timer starts. Capture ratio says whether the invoice was enough, by setting the fee against the recovered cost from Layer 5 after its confidence discount. Below 5% reads as under-invoiced and above 25% as a fee the evidence cannot defend, and both edges are judgments.

Each reading is also written down as a belief before the records are opened. The distance between the two is an awareness gap, measured on the practitioner. The ledger, run on a real engagement ›

Measuring design

Added in v2.2 · October 2026

The same rules apply to the design work itself: an identity, an interface, a report. RUCF models design as acting through four links. People notice it, they process it, they attribute qualities to it, and they act differently because of it. Notice, process and act can be observed. Attribution can only be reported.

design gap   D = A − B_d     attribution against behaviour, matched control = 50
confidence   c = w × 0.8^k

The say-do matrix applies unchanged. Research on the aesthetic-usability effect predicts the lean: polish raises what people credit a design with before they use it, so a highly finished artefact tends toward silent friction, and a plain one that works tends toward phantom friction. Craft is judged blind by panels whose agreement is reported, liking is read at first exposure and again after use, and every reading is taken against a matched control because a design has no absolute score.

The full model, protocol and sources › Applied to how clients choose studios ›

Accessibility, restructured

Conformance is a gate. WCAG 2.2 AA is a pass or fail against a published standard with legal force in the EU. Averaging it into a composite lets an attractive product post a respectable number while failing a legal requirement, so RUCF removes it from the score entirely. Fail conformance and RUCF returns a remediation list instead of an index.

Accessibility experience lives in the tail of every dimension rather than in a dimension of its own. A product can conform perfectly and still be miserable to use with a screen reader, one hand, or a poor connection, and that misery lives in the tenth percentile of usability, of commitment, of everything.

What RUCF does not do

It structures user research rather than replacing it. It does not tell you what to build. It will not catch a broken business model. It is a poor fit below a few hundred active users. It measures the cost of an experience and the accuracy of your beliefs about that cost.

Prior art

None of the mechanisms here are unprecedented. Assembling them is the contribution.

Licence

CC BY 4.0. Use it, teach it, adapt it, run it for clients. Attribute it to RUCF and link back. You do not need permission and you do not owe anything.

Changelog

v2.2, October 2026. Adds a measurement model for design itself: four links (notice, process, attribute, act), the design gap, six protocol rules and instruments for identities, interfaces and reports. Manifesto section 12, limitation 8.9, falsifiers F7 and F8, and research items 8 and 9 added 17 October. Nothing in the scoring model changed, so v2.1 scores remain comparable.

v2.1, September 2026. Adds the practice ledger: attribution rate, hour yield and capture ratio, computed from records. Manifesto section 5.5, limitation 8.8, falsifier F6 and research item 7 added 2 September. Methodology phase 06 added 9 September. Nothing in the scoring model changed, so v2.0 scores remain comparable.

v2.0, August 2026. Complete rebuild. v1 scored four attributes and averaged them, which made it a taxonomy rather than a framework. v2 measures gaps, introduces the say-do matrix, confidence weighting, deploy decay and tail reporting. The twelve signals survive as the friction inventory. Accessibility moved from a scored dimension to a gate plus a tail.

v1.0, 2025. Four dimensions, twelve signals, composite average. Retired.